The invention is concerned with a sterilization unit for dental handpieces and other instruments, such as endoscopes, proctoscopes, laprascopes, biopsy probes, scalpels, acupuncture needles, manicurist's instruments, tatoo artist's needles, and, in general, any instrument which when used breaks the skin of a patient, or comes in contact with body fluids. The unit of the invention is of the same general type described and claimed in U.S. Pat. No. 4,376,096 which issued Mar. 8, 1993 in the name of the present inventor.
All surgical instruments should be sterile before they can be safely used in the treatment of patients. Failure to use sterile instruments exposes patients to the risk of infection which may impede their recovery or, at worst, cause death. In order to prevent patients from suffering infection following surgical procedures it is therefore of the utmost importance that all those processes which are designed to produce sterile instruments be carried out efficiently.
The sterilization unit of the present invention has particular utility in the sterilization of dental handpieces and, for that reason, it will be described in the following specification in conjunction with dental handpieces. However, it is to be understood, as explained above, that the unit of the invention has general utility for sterilizing a wide range of surgical and other instruments.
At present, dental handpieces are not being sterilized on a patient-to-patient basis or even on a daily or periodic basis, throughout the dental profession. However, five states have now mandated between-patient heat sterilization of dental handpieces, and more states are expected to follow.
It is well established that dental handpieces can spread infectious diseases from patient-to-patient, or from patient to the dentist, nurse or other assistants. During the use of a dental handpiece, the head and turbine of the handpiece become repositories for blood and flesh particles. This is caused by direct contact with the patient and by back pressure of the air lines during use. The handpiece should be water flushed after each use to remove such particles, and it also should be sterilized to kill any diseases carried by infected blood.
However, most present day heat sterilization techniques tend to damage the dental handpiece, and particularly tend to damage the high speed turbine located in the head of the handpiece. The most direct and effective sterilization procedure is steam/heat sterilization, this being recommended by the CDC, FDA and ADA because the combination of heat, steam pressure and time will kill any disease. However, conventional steam/heat sterilizers such as autoclaves and the like, generate temperatures sufficiently elevated to damage the handpiece turbine. Accordingly, dentists who are now heat sterilizing their handpieces between patients are currently paying a high price to protect their patients from cross-contamination because of handpiece repair costs. A second deterrent to the use of autoclaves is that the sterilization cycle is too long, which means that the handpieces cannot be sterilized in the average time between patient treatment (20-30 minutes).
Accordingly, it is an object of the present invention to provide a heat sterilizing unit for dental handpieces, and other surgical instruments, that does not damage the instruments, and which requires a total cycle time including cooling to a patient-ready condition of less than 20 minutes.
The unit of the invention includes a unique heat control system which places the sterilizing chamber at a temperature which creates steam and pressure in a time frame that sterilizes the handpiece without damaging the turbine. Mineral-free water is flushed through the piping and turbine of the handpiece to clear out debris and to insure sterilization inside as well as outside each handpiece. The sterilization system, in the particular embodiment to be described, is capable of sterilizing up to three handpieces at a time, thereby providing twelve sterilized handpieces each hour.
A further object of the invention is to provide such an improved sterilization unit in which both the sterilizing process and cooling process are performed in a single unit and in a relatively rapid time frame, so as to permit inter-patient sterilizing of the handpieces.